Santa Barbara County Sheriff Bill Brown identifies murder suspect Elliot Rodger (photo right) and some of the weapons he used, at a press conference in Goleta, California May 24, 2014. Rodger, 22, went on a rampage in Isla Vista near the University of California at Santa Barbara campus, stabbed three people to death at his apartment before shooting to death three more in a terrorizing crime spree through the neighborhood. AFP PHOTO / ROBYN BECK (Photo credit should read ROBYN BECK/AFP/Getty Images)Santa Barbara County Sheriff Bill Brown identifies murder suspect Elliot Rodger (photo right) and some of the weapons he used, at a press conference in Goleta, California May 24, 2014. Rodger, 22, went on a rampage in Isla Vista near the University of California at Santa Barbara campus, stabbed three people to death at his apartment before shooting to death three more in a terrorizing crime spree through the neighborhood. (ROBYN BECK/AFP/Getty Images)

ISLA VISTA (CBS/AP) — The student who killed six people near the University of California, Santa Barbara, detailed in a manifesto how deputies almost thwarted his killing plan.

Elliot Rodger wrote in the 141-page rambling document how he narrowly missed being found out when deputies knocked on his door last month.

Santa Barbara County Sheriff Bill Brown says deputies checked on Rodger after being called by a concerned family member. The officers left after determining he didn’t need to be locked up for mental-health reasons.

Rodger expressed relief that his apartment wasn’t searched because deputies would have found his weapons and his writings and would have foiled his plan.

Brown says he won’t second-guess his deputies’ decision-making in the encounter.